1. The Field of the Invention
The present invention is related to an end cap assembly for a fastener installation tool. More particularly, the present invention is related to an end cap assembly which includes a protective cover plate for protecting the joint between the end cap and the housing of the fastener installation tool and which provides a reliable means for removing the end cap.
2. Technical Background
Since the industrial revolution, rivets and other types of fasteners have been used for attaching two or more work pieces together in industrial or other applications. Such fasteners are used to assemble a wide variety of articles from jeans to railroad box cars. These fasteners range in size and load bearing capacity depending upon their application.
The size of the fastener installation tool varies with the characteristics of the fastener. Fastener installation tools are often hydraulic or pneumatic. Generally, hydraulic and pneumatic tools have a piston chamber and piston assembly which operates under hydraulic or pneumatic pressure. Access to this chamber is necessary to repair the piston assembly or otherwise access the internal workings of the tool. Thus, most hydraulic and pneumatic fastener tools have housings with removable end caps which allow such access.
When these fastener installation tools are used in heavy industrial applications, they are generally subject to rigorous use in unfriendly environments. For example, tools of this type are used in such places as railroad yards and shipping yards. Additionally, these heavy industrial uses require larger fasteners or fasteners with greater holding capacities. In either case, the installation tools for these fasteners are generally larger and heavier and are susceptible to being dropped. Thus, these installation tools for industrial fasteners may often be dropped from relatively high places and are otherwise subjected to extreme wear and tear during average use.
A common problem for these tools is that the base of the piston chamber housing endures substantial plastic deformation, making it difficult if not impossible to remove the end cap from the tool. For example, if the tool is repeatedly dropped, the joint between the end cap and the housing may become "peened over" making removal of the end cap virtually impossible.
Conventional end caps are difficult to remove even if the joint or the housing is only slightly damaged because most conventional end caps are not configured with a place to attach a tool for applying a sufficient removal torque. For example, many end caps are flat with a circular perimeter. Tools used to remove these conventional end caps often slip off these end caps because secure engagement with the end cap is not possible. The configuration of these end caps may facilitate the initial insertion of the end cap within the housing, but the initial insertion usually involves an undamaged end cap and housing.
Heavy industrial hydraulic and pneumatic tools often generate pressures upwards of 5000 psi in the piston chamber. In many fastener installation tools, this pressure also bears against the end cap. Should the end cap disengage the chamber housing under this kind of pressure, the results could be extremely damaging. Accordingly, the end cap assembly must provide a lock to adequately secure the end cap to the housing. Most fastener installation tools have a locking mechanism for locking the end cap to the housing. However, these locking mechanisms are often inconvenient to access and remove. Still other locking mechanisms are unprotected and susceptible to damaging wear and tear.
From the foregoing, it will be appreciated that it would be an advancement in the art to provide an end cap assembly for a fastener installation tool which provides protection for the joint between the end cap and the housing and the portion of the housing adjacent to the joint. It would be another advancement in the art to provide such an end cap assembly which included means to facilitate the removal of the end cap from the fastener installation tool, even if the housing has become substantially deformed. It would also be an advancement in the art to provide such an end cap assembly which included locking means for securing the end cap to the fastener installation tool that is convenient to access and remove.
Such an end cap assembly for a fastener installation tool is disclosed and claimed herein.